Kentucky's Golden Triangle continued to grow during the last decade as the population drained away from the eastern and western coalfields and farm counties along the Mississippi River.
That's the overarching news from the state's official 2010 U.S. Census count, released Thursday.
The state as a whole grew a modest 6.1 percent from 2000 to 2010, to a total population of 4,339,367 as of last April 1, according to a Herald-Leader analysis of U.S. Census Bureau data.
The numbers released Thursday include more detail: population breakdowns by city, county, race, ethnicity and voting age that shed light on the state's internal shifts and the growth in the number of Hispanic residents — up 112 percent since 2000.
The numbers show that most of the fastest-growing counties in the state were in the area bounded by Lexington, Louisville and Northern Kentucky — the so-called Golden Triangle. That was the case in the 1990s, too.
Scott County grew more than 40 percent, for example. Spencer County, a bedroom community for people who work in Louisville, led all counties in percentage of growth from 2000 to 2010 — as it did in the 1990s — with a 43.6 percent increase.
It's not hard to explain why the Golden Triangle continued to outpace most of the state in population gains, officials said.
"That is where the jobs are," said Michael Price, interim director of the Kentucky State Data Center at the University of Louisville.
The handful of counties outside the area that grew more than 10 percent have engines that boost jobs, such as universities and interstate highways.
Warren County, for instance, which grew more than 21 percent, is home to Western Kentucky University and is on Interstate 65 between Louisville and Nashville. Its county seat, Bowling Green, is now the state's third largest city, behind Louisville and Lexington.
Trigg County, which is on Lake Barkley and Interstate 24 in southwestern Kentucky, grew by 12.6 percent.
Kentucky, like the nation, has lost factory jobs, but manufacturing is still one of the state's biggest employment sectors, with more than 210,000 workers in January, according to Ron Crouch, director of research and statistics for the state Office of Employment and Training.
And roads play a key role in where those factories are.
"If you look at the growth in the state, it's taking place along the interstate highways," Crouch said.
The only county in the eastern end of the state that grew more than 10 percent was Elliott, but that was because the state opened a prison there in 2005.
The 1,000-plus inmates at Little Sandy Correctional Complex accounted for all the county's growth.
Decline of east and west
As the center of Kentucky continued to fill up during the past decade, the ends kept losing population.
Most of the counties that lost more than 5 percent of their residents were in Eastern and Western Kentucky, along with a few on the Tennessee border.
"It's a pretty distinctive pattern," Price said. "We seem to have two Kentuckys."
The population losses are a product of out-migration and a low birth rate, a consequence of younger people moving away. Some counties have more deaths than births.
People are leaving those counties to find work.
"Our biggest problem is not having jobs," said Cumberland County Judge-Executive John A. Phelps Jr. "Our young people, when they leave high school ... chances are they're going to move."
Cumberland County's population went down 4.7 percent in the 2010 Census.
One place the exodus shows up is in declining school populations.
The Harlan County school system, for instance, has seen a steady drop in students for generations as coal-mining jobs declined from historic highs, broken only for a few years in the 1970s during a temporary coal boom, said Superintendent Tim Saylor.
Student enrollment determines how much state money schools get. Since 2000, Harlan County has had to cut more than three dozen teaching jobs, close schools and keep aging buses on the road longer because of declining enrollment and revenue.
"We've cut about everything we can cut," he said.
Mining is still critical to Eastern Kentucky's economy, but the economic base must be broadened, said Bruce Ayers, president of Southeast Kentucky Community and Technical College.
"We simply don't have the economic base, the infrastructure, that young people can plug into," Ayers said.
The college has worked to boost the economy with programs such as a special business-loan fund, training in the health-care sector and a basic engineering program.
But poor transportation access to the county — which lost almost 13 percent of its residents since 2000 — impedes its chances for economic growth, Ayers said.
"Our roads still are among the worst in the nation," he said.
The population losses hurt, costing counties revenue from occupational taxes and making it harder to compete for some grants, and for industry, officials said.
"Our tax base continues to decline," said Phelps.
Why it matters
The state's population, and that of cities and counties, has an effect on a lot of fronts.
Population is a key factor in how hundreds of billions in federal money is distributed for everything from road construction to services for senior citizens.
Some home loans through the U.S. Department of Agriculture Rural Development are open only to people in counties with less than 20,000 people, while some of its economic-development programs apply only in counties with a population of more than 50,000.
It's possible people in some Kentucky counties will lose access to home loans because of population growth since 2000.
Administrators will review the new totals and determine how they affect eligibility for programs, said Katherine Belcher, spokesman for the USDA Rural Development office in Kentucky.
"Housing's probably the one that's going to be most affected," Belcher said.
Population also helps determine the boundaries of seats in the U.S. House, the state Senate and House, and other political districts.
The state grew enough during the last decade to avoid losing a seat in the U.S. House, as it did after the 1990 Census.
Kentucky will keep its six seats, faring better than some neighbors. Ohio will lose two seats, and Illinois and Missouri will lose one each.
However, the boundaries of the U.S. House districts in Kentucky and state Senate and House districts probably will change to accommodate population shifts.
"You're going to have larger areas for House and Senate seats in Eastern and Western Kentucky," Crouch said.
Computer-assisted reporting coordinator Linda J. Johnson contributed to this story.